The　polarization　behavior　of　Ba0.5Sr0.5Co0.8Fe0.2O3-delta-BaCe0.4Zr0.4Y0.2O3-delta(BSCF-BCZY)　electrode　under　steam　electrolysis　conditions　was　studied　in　detail.　The　composite　oxygen　electrode　supported　by　BCZY　electrolyzer　has　been　assessed　as　a　function　of　temperature　(T),　water　vapor　partial　pressures　(pH(2)O),　and　bias　polarization　voltage　for　electrodes　of　comparable　microstructure.　The　Electrochemical　impedance　spectra　show　two　depressed　arcs　in　general　without　bias　polarization.　And　the　electrode　resistance　became　smaller　with　the　increase　of　the　bias　polarization　under　the　same　water　vapor　partial　pressures.　The　total　resistance　of　the　electrode　was　shown　to　be　significantly　affected　by　temperature,　with　the　same　level　of　pH2O　and　bias　polarization　voltage.　This　result　highlights　BSCF-BCZY　as　an　effective　oxygen　electrode　under　moderate　polarization　and　pH(2)O　conditions.　(C)　2017　Elsevier　B.V.　All　rights　reserved.